The present invention relates to a lifting apparatus, more particularly a lifting apparatus which is suitable for operating within confined spaces or areas such as between beds in a hospital ward.
Lifting apparatus are used in hospitals and hospices and the like to facilitate movement of patients onto and off of beds, trolleys, wheelchairs and into and out of baths.
In general lifting apparatus of this type take the form of fixed structures located above the bed or bath. The lifting apparatus comprises a mechanically or manually operable pulley system from which depends a harness for securing to a patient during lifting. The pulley system is movable horizontally along rails which are generally fixed to a wall adjacent the bed/bath.
The main disadvantages of lifting apparatus of this type is that they are fixed (to a wall or may be free standing frame secured to the floor) and are not readily relocatable without first dismantling the apparatus, which is obviously undesirable and time consuming.
Mobile lifting apparatus are also used in hospitals to provide support to a patient to be lifted. These generally lift through a single arcuate pathway which presents difficulties in lifting patients onto and off of beds, or trolleys, or into and out of baths.
Lifting aids of this type are generally unsuitable for patients who are unable to grip the lifting apparatus with at least one hand or who lack comprehension and are totally non self-weight-bearing. Furthermore, in use, lifting aids of this type may require one person to operate the lifting aid another provides additional support to the patient.
It is an object of the present invention to minimise or obviate one or more of the foregoing disadvantages.
The present invention provides a lifting apparatus which is capable of variable and independently selectable height and reach and is particularly suitable for use in lifting patients in and out of beds, trolleys, wheelchairs and into and out of baths in hospitals and hospices and the like, which lifting apparatus comprises a base supporting a lifting means, said lifting means comprising at least two upwardly extending variably extendible support means; an arm having a proximal end portion and an intermediate portion, which portions are pivotally connected, directly or indirectly, to an upper end portion of respective ones of said variably extendible support means; and a load support means depending from a distal end portion of the arm, said variably extendible support means being provided with drive control means formed and arranged for extending and retracting said variably extendible support means relative to each other for controlling translational movement of the arm such that the reach and elevation of the lifting apparatus may be altered substantially independently of each other whereby a load depending from the distal end of said arm can be selectively and independently moved in generally vertically and/or horizontally extending directions.
Various forms of drive control means may be used. Conveniently there may be pressurised fluid (hydraulic or pneumatic), single or double-acting, rams provided with drive means such as pressurised fluid pumps and control means such as valve systems. The pressurised fluid rams may moreover have two, three or more concentrically arranged telescopically extendible sections. Additionally, where the pressurised fluid rams have two or more sections, then the ram of one (or more) of said two or more sections can be locked in a desired position by a locking means while the remaining section(s) can be extended and/or retracted as desired. Preferably, at least one of said at least two upwardly extending variably extendible support means is a double-action ram.
Alternatively there may be used rack and pinion or winch and pulley systems with drive means such as an electric motor or a direct drive system such as a linear motor, and control means may be electronic circuit systems. Naturally microprocessor systems may also be included in the control systems. It will be appreciated that the apparatus may be readily provided in different sizes with various operating parameters, notably range of horizontal and vertical movement, and maximum reach and maximum elevation of the load support means. Conveniently the variably extendible support means are formed and arranged to provide a maximum elevation of the load support means in the range of from 1.5 to 3.0 m.
The footprint shape of the base can be of any configuration such as generally circular, polygonal (regular or irregular), e.g. hexagonal, square or triangular. The shape of the base is preferably cylindrical so as to avoid angular edges which may cause an injury to a user or patient.
The base of the lifting apparatus may be provided with powered and/or unpowered wheels or other similar means to facilitate relocation/transportation of the lifting apparatus in a loaded or unloaded condition.
The arm typically has a length of from 0.5 to 2.0 m, preferably from 1.0 to 1.6 m. The arm is desirably fabricated from a material which has a relatively high tensile strength to permit safe lifting of patients with body-weights which may be up to 100 to 150 kg or more. Suitable materials are steel, especially high tensile steel, DURALUMIN (Trade Mark) and other high tensile alloys.
Conveniently there may be provided an extension attachment which is formed and arranged to be connected to the distal end of the arm to provide additional reach. The extension attachment may also be provided with similar support apparatus as for the arm such as a support harness or releasable fastening (such as a karabiner). A similar extension attachment may also be provided for attachment to the uppermost end of each of the variably extendible support means.
It will be appreciated that the base should generally be configured to ensure that the lifting apparatus does not over-balance in use with an intended load. In general the base is formed and arranged so that together with said support means, it provides sufficient counter-balancing for any intended load. Conveniently there may be included in the base counter-weight or ballast means.
The drive control means conveniently is provided with a user interface in the form of a control panel located on the base. Alternatively, the user interface may be a remote control device linked to the variably extendible drive means via suitable wiring or other communication means such as radio, infra-red, or microwave transceivers.
An on-board power pack may conveniently be provided within the base and preferably comprises a system of rechargeable battery power cells. Advantageously, the power pack is provided with an integral charging device such that the battery power cells can be re-charged directly from a mains power supply.
The drive control means is desirably of at least sufficient power to produce a lifting capacity of at least 150 kg, and advantageously 200 kg or more, when the arm is fully extended (and any variably extendible support means is also extended to its maximum extent).
In a preferred form of the present invention, the arm is directly and pivotally connected to the respective upper end portions of the at least two variably extendible support means.
Desirably said at least two variably extendible support means comprise at least one each of a main variably extendible support means and a secondary variably extendible support means whereby the main variably extendible support means provides the main load bearing support for the lifting apparatus.
Preferably, the main variably extendible support means provides the main load bearing support for the arm via a support link which is pivotably connected across the upper end of the main variably extendible support means and said intermediate portion of the arm. The said secondary variably extendible support means is pivotally connected to a proximal end portion of the arm. The height and reach of the lifting apparatus may be varied by altering the degree to which the main and secondary variably extendible support means are extended relative to each other.
In a preferred form of the present invention provided with said support link, the variably extendible support means (main and secondary) and the arm may be retracted and stowed within said base of the lifting apparatus by extending the main variably extendible support means to its fullest extent while simultaneously retracting the secondary variably extendible support means, said arm pivots downwardly about its non-distal end (attached to said upper end portion of the secondary variably extendible support means) to a final resting position where said arm lie flush against along its length against the secondary variably extendible support means such that the main and secondary variably extendible support means and the arm are substantially parallel to each other; both the main and the secondary variably extendible support means may then fully retracted by the drive control means within said base of the lifting apparatus.
When the apparatus does not require the extending arm to be fully retracted, the coupling between the ram and the arm can be of the permanent fixed coupling type. Where it does require to be retracted then a pivot pin connecting the hydraulic ram to the arm, must disconnect from the arm. This may be done in different ways but one preferred way would be to have the jaws of pivot pin engaging catches provided on the arm formed and arranged so that they are forced open under the power of the pin""s movement. The jaws may be locked around the pin using a cotter pin and/or heavy duty leaf spring and/or a resiliently biased piston on one (or possible both) side(s) of the pin catch.
Various kinds of support means at the distal end of the arm may be used, including, inter alia, a support harness or the like such as those commonly used in hospitals for lifting patients in and out of wheelchairs, baths, beds and onto/off of trolleys. Alternatively, the support means may be a hook or releasable fastener such as a karabiner for attachment to a support harness or the like.
The base may be supported on a turntable or the like such that the lifting apparatus can be rotated through a full rotation or part thereof. The turntable is conveniently controlled through the same user interface as the drive control means. Additionally or alternatively the lifting apparatus may be provided with a plurality of stabiliser legs or stays which can be extended in use of the apparatus when required to provide additional security against overbalancing. The stabilising legs or rods may be integral parts of the base or turntable or may be connected thereto by conventional means such as by welding or by being bolted into place.
The scope of use of the lifting apparatus is not intended to be strictly limited to use in hospitals and the like, and it is intended that the apparatus may be used in a wide variety of environments such as in warehouses where space is limited or on construction sites where there are frequently relatively heavy loads to be lifted and/or moved.